In myocardial-specific WWP2 knockout mice, the ubiquitination level of PARP1 is decreased, while the effects of ISO-induced PARP1 activation and PARylation are enhanced, thereby exacerbating ISO-induced myocardial hypertrophy, HF, and myocardial fibrosis 66 (Zhang et al., 2020). Here, PARP1 is linked to hydrops fetalis.